| Project/Area Number |
13305003
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied materials science/Crystal engineering
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| Research Institution | Tokyo University Agriculture And Technology |
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Principal Investigator |
SATO Katsuaki Tokyo University Agriculture And Technology, Faculty of Technology, Professor, 工学部, 教授 (50170733)
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| Co-Investigator(Kenkyū-buntansha) |
ARAI Hisazumi Osaka University, Graduate School of Science, Professor, 理学研究科, 教授 (70124873)
SATO Hideyuki Tokyo Metropolitan University, Graduate School of Science, Professor, 理学研究科, 教授 (80106608)
TAKAHASHI Koki Tohoku University, Institute for Materials Research, Professor, 金属材料研究所, 教授 (00187981)
IMADA Shin Osaka University, Graduate School of Engineering Science, Lecturer, 基礎工学研究科, 講師 (90240837)
浅野 肇 筑波大学, 物質工学系, 教授 (90005934)
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| Project Period (FY) |
2001 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥53,170,000 (Direct Cost: ¥40,900,000、Indirect Cost: ¥12,270,000)
Fiscal Year 2003: ¥10,270,000 (Direct Cost: ¥7,900,000、Indirect Cost: ¥2,370,000)
Fiscal Year 2002: ¥26,390,000 (Direct Cost: ¥20,300,000、Indirect Cost: ¥6,090,000)
Fiscal Year 2001: ¥16,510,000 (Direct Cost: ¥12,700,000、Indirect Cost: ¥3,810,000)
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| Keywords | MOMBE growth / Chalcopyrite type Semiconductor / CdGeP2: Mn / ZnGeP2: Mn / MnGeP2 / Magneto-optical spectrum / SQUID magnetometer / Ferromagnetism / 有機金属ガスソースMBE法 / 光電子スペクトル / 第1原理計算 / 空孔 / 置換欠陥 / 磁性半導体 / SQUID磁束計 / 電子スピン共鳴法 / フォトルミネセンス / X線構造解析 / 第1原理バンド計算 |
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| Research Abstract |
This study was planned to elucidate the physical properties of the room-temperature ferromagnetic semiconductors based on Mn-doped chalcopyrite-type compounds such as CdGeP_2: Mn.Initially preparation of this material was carried out by deposition and diffusion of Mn on to the bulk single crystal of chalcopyrite-type compounds.
In the present study. we first studied ZnGeP_2: Mn using the same deposition-diffusion technique and confirmed ferromagnetism with Curie temperature above room temperature and elucidated that the room temperature ferromagnetism is not peculiar to the CdGeP_2: Mn material. First we performed Mn-doping on to another chalcopyrite-type compound and found that ZnGeP2:Mn shows also a ferromagnetic order at room temperature, indicating room-temperature ferromagnetism is not characteristic of. Next. it is elucidated through an in-situ photoelectron spectroscopy of University of Tokyo group that the surface region is dominated by Mn-Ge-P composition and the magnetism is o
… More
riginated * a deep DMS layer in which substituted Mn is divalent.
We also performed ab-initio band calculation and investigated whether ferrornagnetism appear in CdGeP_2: Mn and found although antiferromagnetism is stable if Mn occupies Cd-site. ferrornagnetism is possible if Mn occupies Ge-site or the host compound possesses intrinsic defects. such as vacancies and cation anti-sites.
However it was difficult to get a homogeneous distribution of Mn by the deposition-diffusion method. So we decided to fabricate thin epitaxial film crystals of CdGeP_2: Mn To stall with we attempted MBE growth of undoped CdGeP_2 using metal organic (MO) sources for all the three constituent elements. In spite of repeated efforts no deposition occurred because all the MO gas spices cannot be decomposed at the condition at which re-evaporation of Cd is suppressed. We supplied Cd and Ge by solid sources using Knudesen effusion cells and P_2 as MO gas by thermally cracking tertiary butyl phosphine (TBP). Only polycrystalline films of CdGeP_2 an existence of which has been confirmed by photoluminescence and Raman measurements.
In parallel with the research of CdGeP_2 we carried out growth and characterization of MnGeP_2 thin films. which has been predicted to exist by theoretical calculation. As a result we confirmed epitaxial growth of chalcopyrite type MnGeP_2, thin films by XRD experiments. Magnetic measurements using SQUID magnetometer revealed ferromagnetism at room temperature in these films. origin of which is still under study. Less
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